Apparatus for coating containers



May --12, 1942.

l. J. SNADER ET'AL 2,282,897 v APPARATUS FOR COATING CONTAINERS Fiied Oct. 30, 1957 12 Sheets-Sheet 1 arwe/wtoa May 12, 1942. l. .1. SNADER ETAL 3 3 APPARATUS FOR C QATING CQNTAINERS I Filed on. so, 1937 12 Sheets-Sheet 2 y 942 l. J SNAD ER i rm.

ABPARATUS FOR commiconflmnns Fiid Oct. 30, 1937 12' Sheets-Sheet 5 r W .1... Y \W 3 m WHEN I. J. SNADER ETAL AIPARA'IUS FOR COKTING CONTAINERS May 12, 1942.

Filed Odt, 30, 1937 12 Sheets-Sheet 4 l Z )4; /M

May 12,1942 J. SNAI'SER ETAL APPARATUS FOR comma CONTAINERS l2 Sheets-Sheet 5 Filed 001;. 30, 1937 I May 12, 1942. l. J. SNADER ETAL 2,282,397

APPARATUSFOR COATING CONTAINERS Filed Oct. :50, 1937 12 Sheets-Shet e May 12, 1942. 1. .1. SNADER ETAL APARATUS FOR comma CONTAINERS Fild Oct. 30, 1937 lZ'She eiS-ShQet 7 MMWW May 12,1942.

1. .1. SNADER ETAL APPARATUS FOR COATING CONTAINERS Filed on. so, 1931 12 Sheets-Sheet 8 May--l2 1942. 1., J. SNADER EI'AL APPARATUS FOR COATING CCNTAINERS Filed Oct. 30, 193'? 1 2 Sheets-Sheet 9 GROW I y-" 1942. 1. .1. SNADER :rm. 2,282,897

APPARATUS FOR COATING CONTAINERS Filed Oct. 30, 1937 12 Sheets-Sheet 10 May-=12, 1942. l. SNADER ETAL 2,232,397

APPARATUS FOR COATING CONTAINERS I Filed Oct. 30, 1937 12 Sheets-Sheet l1 l. J. SNADER ETAL APPARATUS FOR COATING CONTAINERS A Filed Oct. 30, 1937 I 12 Sheets-Sheet 12 W zagw ww Patented May 12, 1942 2,282,897 APPARATUS FOR COATING CONTAINERS Ira J. Snader and James F. Earp, Jr., Detroit, Mich., assignors to The American Farmer Bottle Company, Toledo, Ohio, a corporation of Ohio Application October 30, 1937, Serial No. 172,025

9 Claims.

This invention relates to apparatus for coating containers, especially containers fabricated of paper and designed and intended for use in the packaging of perishable products, although in certain of its broader aspects it relates to the application of coatings to articles of various kinds and fabricated of different materials.

Paper containers of various kinds have heretofore been widely used in the packaging and distribution of many solid products, being attractive in appearance, light in weight, and comparatively inexpensive. The packaging of solid materials either in the form of single articles, or lump or granular substances, presents little difiiculty and many machines for fabricating suitable containers intended for such use have heretofore been designed or suggested. The packaging of liquids, however, in paper containers, is much more difficult to successfully accomplish since by reason of the fibrous nature of the paper it readily absorbs liquids and, after the paper has become wet, it loses the greater part of its strength. Hence it is necessary, if a paper container for liquids is to be produced at a reasonable cost, to apply to its surfaces a coating layer of a substance impervious to liquid in order that the paper fibers of the container may not become wet and soft. Paper containers for the packaging and distribution of liquids must of necessity be of the self-supporting type and comparatively' strong since the pressure of the liquid within the container is considerable even when the container is at rest, and the danger of failure is of course increased when the container is handled or transported. The material customarily chosen for the coating of paper containers in the usual case'comprises paraflin or at least is a paramn containing substance, it having been found that such coating material not only is liquid proof but has a certain stiffness when hardened, thus increasing the ability of the container to maintain its shape during handling.

and transportation, despite the internal pressure of the liquid. While coatings of various materials may be applied to paper containers in various ways it is preferable that the coating be applied by means of a dipping operation since by immersion in a bath of molten coating material it is assured that the coating is applied thoroughly to all areas of the container.

The present invention contemplates an apparatus for coating containers generally, but particularly containers which have been folded into tubular form and have one end (the bottom) closed and the other end open, and the apparatus hereinafter to be described is intended to receive containers thus partially completed, effect the immersion thereof in a bath of the molten coating material, drainage in a'heated atmosphere above the bath, introduction into the interior thereof of additional coating material, if necessary, and subsequent chilling of the coating material to'etfect its hardening. Coating of the containers in a nearly completed stage of fabrication is advantageous in that the container need be subjected to but few further operations which tend to disturb the coating already applied.

Practically all containers fabricated of paper have certain portions of greater thickness than other portions. In the usual case the bottom of the container comprises two or more plies of paper and the side walls but a single ply or thickness. That portion of the container which is of greatest thickness has a tendency to absorb more coating material than those portions of less thickness and likewise is slower in cooling after its temperature has been raised by immersion in a molten bath of coating material. In accordance with the present invention these characteristics of the paper container are given full consideration and, after dipping and draining, the. heavier bottom of the container is covered with an additional amount of coating material if excessive absorption of this material has occurred, likewise the cooling means is so designed and constructed that that portion of the container which tends to retain heat longest is subjected to the action of a cooling medium of higher heat conductivity than is that portion, or those portions, of the container which are of lighter section; For instance in the case of a tubular container with a multi-ply bottom theheavier bottom portion of the freshly coated container is immersed in a liquid bath cooled to a low temperature whereas the thinner portions of the container wall aresufiiciently cooled and the coating material hardened by the simple application thereto of a current of cooled air or other gas. The cooling of Lne bottom of the freshly coated container, and of the side walls,

are effected simultaneously so that the cooling of the entire container and the hardening of its coating layer is effected in a minimum of time, a consideration of much importance when the coating and cooling mechanisms comprise only portions of a complete automatic machine for the fabrication, coating, charging and sealing of paper containers.

Prior to cooling the container is automatically handledand manipulated by automatic mechanism which is maintained in heated condition in order that it will not become clogged by hardening of the coating material thereon and a novel means for maintaining those various portions of the mechanism which come in contact with parafiin at any time has been devised. Likewise means is provided for supplying the coating mechanism with freshly melted coating material to replace that carried away upon the surfaces of containers which have been immersed. The cooling system for effecting cooling of the volumes of air and liquid employed to cool the freshly coated containers is provided which system embodies a number of novel and important features. The invention likewise includes a number of additional elements, not abovespecifically mentioned, which contribute to the effectiveness of the mechanism as a whole.

By way of example, one embodiment of the coating apparatus is disclosed in the accompanying drawings, but it will be appreciated by those skilled in the art that the design and arrangement of numerous elements of the invention may be substantially modified without departure therefrom, particularly in adapting the same for the coating of containers of different shapes and sizes.

In the drawings:

Figure 1 is a side elevation of the coating apparatus in its entirety;

Figure 2 is a plan view of the same;

Figure 3 is a central longitudinal vertical section through the apparatus;

Figure 4 is a central vertical longitudinal section through the coating unit or mechanism for a novel v actually applying coating material to the containers;

Figure 5 is a section on line 5-5 of Figure 4;

Figure 5a is a side elevation of the means for injecting into a container a supplementary amount of coating material, this means being 11- lustrated in Figure 5 but 'shown in Figure 5a upon a larger scale, and-with one of the operating parts in a different position;

Figure 6 is a section on line upon a larger scale;

Figure 7 is a section on line 1-1 of Figure 6;

Figure 8 is a section on line 8-8 of Figure 6;

Figure 9 is a plan view of a trackway which comprises portion of a conveyor for freshly coated containers;

Figure 10 is a side elevation of the same;

Figure 11 is a section on line' illl of Fi ure 10;

Figure 12 is a central vertical longitudinal section through the cooling-unit of the apparatus;

2Figure 13 is a section on 1 Figure 14 is a section on. line H-ll of Figure 12;

Figure 15 is a section on line I ure 5;

Figure 16 is a section on line iS-IG of Figii-S of Figure 4 line l3i 3 of Figure ure 5;

Figure 1'7 is a section on line i'l -l'l of Fi ure 1; Figure 18 is a section on line l8-I8 of Figure 17;

Figure 19 is a similar section on a larger scale, 7

showing only portion of the apparatus shown in Figure 18;

Figure 20 is a diagrammatic view showing the various elements of the apparatusto which heat charging, closing and sealing is applied and the steam supplying and condensation removing lines or conduits;

Figure 21 is a diagrammatic view showing the elements of the cooling means for the cooling unit;

Figure 22 is a side elevation of certain portions of this cooling means;

Figure 23 is an end view of the same;

Figure 24 is a perspective view of a container of the type which the apparatus has been particularly designed to receive and coat; and

Figure 25 is a section on line 25-25 of Figure 7.

The method of coating includes two principal steps, i. e., the step of actually applying the coating and the step of chilling and solidifying the coatings thus applied. In the apparatus for practicing the method the coating applying unit and the coating chilling unit, while in some respects independent of each other, are closely associated in order that a maximum efiiciency of operation may be realized. The coating apparatus as a whole is, as a matter of fact, preferably designed to comprise an integral portion of a complete automatic machine forthe formation of containers from scored paper blanks, coating of these containers, and the subsequent charging,

closing and sealing of the same. Notwithstanding this. the apparatus may well be employed independently of any container fabricating means and independently of the container means, and may be used to coat containers which have been formed elsewhere, and' which may also be charged, closed and sealed at a relatively remote point, The method of and apparatus for actually applying to a container a coating of paraffin or like substance will first be described.

In Figure 24 of the drawings a container of the type which the machine has been specifically designed to handle is illustrated in perspective and partially broken away. This container is fabricated of relatively thin stifl' paper of good quality and comprises a body portion having four rectangular panels a, a foldable top portion b and a closure or bottom 0, at its lower end, the container being coated with the selected material while in the stage of completion in-which it is shown inFigure24, the bottom c having been fully formed, but the top or upper end being open. It will be perceived that the body portion and top portion of the container are formed of a single thickness of paper but that the bottom is built up of several thicknesses, preferably three, and is of much heavier section than either the side wall or top; In the method of coating employed this difference in section between the bottom and other parts of the container is fully taken into account. as will hereinafter appear.

While various mechanisms for and methods of actually applying the molten coating material to the container walls may be employed, it is preferred that each container to be coated be acmolten coating material and the upper portion of which comprises a housing for the means for passing containers through the bath in a definite plete understanding of this mechanism reference may be had to the Henry T. Scott application, Serial No. 108,258, filed October 29, 1936. It need only be said here that containers are successively brought into predetermined position opposite an aperture in the chamber wall by mechanism which includes an oscillating container holding member I2, are thereafter thrust laterally through this aperture into successively presented container carriers I3, mounted upon an endless conveyor chain which is operated intermittently to lower the carriers I3 into the bath. of coating material within the receptacle II, the level of the upper surface of such coating material being indicated at I4, to transmit the containers through the bath in the direction 'of the arrow A and'thence upwardly, as indicated by the arrow B, to a point generally indicatedat C,

at which point there is a discharge aperture in the chamber wall, and in position to be engaged by pusher fingers I6 mounted upon a sliding head l1, and successively thrust through the discharge aperture and into a container receiving member I8.

Each container is lowered into the'bath of molten coating material bottom end foremost.

and removed from the bath bottom end foremost so that in its upward movement in the direction of the arrow B (Figure 4) the open end of the container is downwardly directed and excess coating material may escape from its inner wall surfaces as well as from its outer wall surfaces so that, by the time the container has reached the position indicated at C, it is quite ready for ejection from the chamber l0.

The pusher head I1 is slidably mounted upon guide rods I9 and immediately below the slide is a box-like member which comprises a steam chest, steam at the desired temperature being conducted to this chest by means of a pipe 2I and the temperature of the atmosphere within the chamber I0 above that of liquification of the coating material so that they containers moving upwardly to the point of discharge after having been coated pass through this heated atmosphere and normal drainage of the. coating material therefrom may occur. It will be understood that the operation of the coating unit is intermittent or step-by-step (although it may be continuous if desired), uncoated containers being successively introduced and, simultaneously with the introduction of each uncoated container, a fully coated container ejected therefrom.

The receptacle II for the molten coating material has a double bottom, the space intermediate the bottom plates comprising a steam chamber,-conduits 26 being provided for introducing steam into the same from opposite sides and a conduit 21 conducting away exhaust steam and water of condensation. The temperature within the steam chamber is at all times maintained sufficiently high to keep the coating ma-- terial in receptacle II in molten condition, automatic steam flow regulating'means hereinafter to be referred to being the steam flow.

Referring now to Figures 5 and So it will be perceived that the member I8 is in the nature of ah elongated rectangulaf'open-sided frame and this frame is mounted upon a rock shaft 30 by means of which it may be moved from the position in which it is shown in Figure 5 to the position in which it is shown in Figure So. When in the position in which it is shown in Figure 5 it may receive a container ejected from the chamber I0, being then in register with the discharge aperture of chamber I0, and when rocked provided for regulating downwardly to the position in which it is shown in Figure 5a such container, which is indicated at R, is vertically disposed with bottom lowermost. When so positioned also the freshly coated container lies in front of a vertically dis posed portion 3| of a flat angular member 3| shown in Figures 6 and 7, .the lower horizontally disposed portion 3| of which is secured to the the walls of which are steam heated.

The rear wall 33 of'this chamber comprises also an exterior wall of the chamber I0, which wall is at all times maintained in heated condi tion by the heating means within chamber I0. Side wall 34, top 35 and arcuate side wall 36 of the chamber in which member I8 is housed are hollow and together comprise one continuous chamber for a heating medium. Steam is introduced into such chamber through a conduit 31 entering the same at its highest point, lower conduits 38 and 39 being adapted to transmit away excess steam and water of condensation. The front wall 40 of the chamber within which the container handling member I8 is located-need not be heated; At all times, therefore, subsequent to the introduction of the container into the chamber Ill, and prior to the operation of the member 3| to eifect removal of the container from the chamber which houses member I8, the container is either maintained in a bath of molten coating material or in a highly heated atmosphere which prevents chilling and solidification of such material after its application.

When a container reaches the position in which it is shown in- Figure 6, immediately in front of pusher member 3|, the coating material upon its vertically disposed walls will tend to drain downwardly, the material flowing down its inner walls being collected on the bottom of thecon- 4- be seen from an inspection of Figures 3, 6 and 7. Atthis point, and while the container is still highly heated and the coating material thereon in fluid condition, it may be desired to introduce a supplemental quantity of coating material into the interior thereof, to be distributed over the container bottom. This is especially true where the container is relatively short and the drainage from its inner wall surfaces onto the bottom is not great. It will be appreciated that to a substantial extent the fiber of which the container is fabricated will absorb coating materials such as paraffin and the greatest absorption occurs at the point where the container is thickest, i. e., at its bottom. Hence if there is not a substantial amount of drainage or downflow of liquid coating substance from the inner faces of the side walls onto the bottom, the bottom may be inadequately coated and hence the container insufficiently prepared for the reception of a liquid. With a taller container it is found that there is usually an ample amount of downflow or drainage of coating material onto the bottom and hence it is generally found unnecessary to supply an auxiliary amount of coating material. The container R shown in Figure a, however, is relatively short, being in fact a container having a capacity of one half pint of liquid. The downflow of coating material onto the three ply bottom is relatively slight and it is necessary to provide means for supplementing the amount of coating material which would naturally gather upon the upper surface of the bottom as the result of the operations previously described.

This supplemental means includes a nozzle device 4| projecting through the top '35 of the housing for the rocking member H, the discharge nozzle 42 of which is aligned with the vertical axis of the container R. when the container is in its lowermost position. The rocking member I8 is provided with an aperture 18' axially aligned with the discharge-nozzle 42 when member I8 is in its lowermost or vertical position so that when a supplemental body of coating material, as indicated at 43 in Figure 5a, is discharged from the nozzle 42 it will pass through aperture l8 and fall to the bottom of the container R.

The nozzle device 4| is of the pressure operated type provided with a valve which opens automatically when the pressure of the liquid within the device. exceeds a predetermined amount and which closes automatically and sharply when the pressure falls below such amount, there being no dropping or discharge of coating material at any other time. charge devices are well-known and any suitable type of such device maybe employed, the details thereof forming no part of the present invention. The means for supplying the coating material to the nozzle device 4|, in synchronism with the movements of the conveyor handling member I8,

Such pressure operated dislic plates 48 which plates, together with con-- aflixed .to the frame of the machine at an elevation higher than that of the receptacle A door 46 at its outer end may be opened for the insertion thereinto of blocks of the solid coating material, two of which are illustrated in chain lines at 41 in Figure 18. The solid coating material thus inserted rests directly upon the uppermost of two parallel horizontally disposed metaltinuous marginal spacing member 49 welded thereto define a chamber 50 into which live steam may be introduced by means of an inlet conduit 5| and from which the exhaust steam and water of condensation may be removed through conduit 52. Welded into aligned circular apertures formed in plates 48 are short tubes 53 and through these tubes 53 molten coating material may pass through the plates into the space below. A certain amount of the molten coating material may flow over the edges of the upper plate.

w bers 59 and the bottom Just below this heating device is disposed a screening means comprising three parallel screens indicated at. 54, 55, and 55, the uppermost screen 54 being of relatively coarse mesh and spaced above the remaining screens by spacers 51, the upper screen being removable. The intermediate screen 55 is of relatively fine mesh and is preferably welded at numerous points to the lowermost coarse mesh screen 56, screen 56 being in turn supported in a frame 58. The screening means thus described is supported above the upper surface of the bottom of the chest 45 by memof the chest slopes downwardly and inwardly toward the frame of the machine, as shown clearly in'Figure 17. An outlet pipe or duct 45' leads from the lowest point of the chest 45 to a point above the body of coating material in the chamber H, and molten paraflin or other coating material will make its escape from the chest 45 into container after having passed through the screening device, any particles of foreign matter or impurities being intercepted by the screen.

During the operation of the coating apparatus the paraflin is removed from the tank or recepwill be hereinafter described and it is only necessary to state at this time that the device 4| receives fluid through the duct or conduit 12. The amount of material which may be discharged by the device may also be closely regulated. Each successive container by the time it reaches the position indicated at R in Figure 6 has received the necessary amount of coating material and is ready for movement toward the cooling unit. Prior to describing the means for chilling and hardening the coating, however, the means for maintaining the necessary supply of paraflin or other coating composition in thekettle or receptacle will be described.

tacle by the containers at a relatively uniform rate and by the timely placing of fresh blocks of the material in the chamber 45 the level of the paraffin in container may be maintained substantially constant. It will be observed from Figures 18 and 19 that each of the steam conduits 5| and 52 is provided, immediately adjacent the 'steam chamber within chest 45, with a collar or.

flange, pipe 5| having a flange 5| and pipev 52 a flange 52'. These flanges intercept any liquid coating material which might otherwise tend to pass along pipes 5| and 52 respectively and to escape from the chest 45 through the apertures formed therein for the reception of these pipes, and to cause such material to drip downwardly onto the screening device below.

Indicator means is provided for enabling the operator of the apparatus to ascertain the actual level ofthe paraflin within the container II at any time. This indicator is shown in Figure 15 and comprises two members, a scale 60 inscribed upon the upper end of the tube SI and a pointer which comprises the upper end of a rod 52, rod 62 extending axially of the tube 6| and having secured to its lower end a float 53. Float 53 is enclosedwithin a cylindrical receptacle or sump 64, the interior of whichis in constant communication with the interior of the receptacle ll so that the level of the paraflin or other coating material within the sump stands at the same elevation as the level of the parafiin within the container II. The level of the parailin in the sump is indicated by the dotted line 85 and it will be readily perceived that, if this level should fall due to withdrawal of parafiin from container II, the float 63 will fall and that the falling level will be indicated by lower positions of the upper end of rod 62 along the scale 68. The body of paraffin in the sump will always be quiescent so that the float will always indicate its true level.

The coating material within sump 64 is maintained at all times in molten and fluid condition by means of a heated coil 66 adapted to receive steam from a conduit 81 at its upper end, the

lower end of coil 66 being in communication with an ofitake conduit for exhaust steam and water of condensation, indicated at 68. A drainage pipe is indicated at 69 which pipe is normally closed by a valve and it is through this pipe that the paraflin contents of the sump and receptacle ll may be withdrawn if desired, the lower end of the sump being at a lower elevaton than the bottom of receptacle I I. Any collected water of condensation may also be removed through drain pipe 69,

A plunger pump is indicated at 18, this pump being mounted upon the side of the sump 64 and comprising a casing having a vertically disposed pump chamber the lower end of which communicates, by means of a port II, with the interior of sump 64 below the level of the liquid within the sump, and also having an outlet port communicating with an ofitake duct or conduit 12 which leads upwardly to the pressure operated nozzle device 4|. The vertical pump chamber is provided with valves and a plunger 74 is vertically reciprocable therein, downward movement of this plunger closing the inlet valve of the pump and placing the liquid therein under pressure and upward movement of the plunger allowing the inlet valve to open and a fresh supply of coating liquid to be drawn into the pump chamber from the sump 84 while at the same time forcing a measured quantity of coating material upwardly to the nozzle device 4|. The plunger I4 is retracted by means of a spring 15 encircling the plunger actuating rod and ,movement of the plunger upon its operating strike is effected by means of a solenoid device generally indicated at 16. When energized the solenoid will efiect downward movement of the plunger and force a measured quantity of coating material into pipe I2 by which it is delivered to the pressure operated nozzle device 4|. When this pressure is initiated the automatically closing valve of the nozzle device M is opened and coating liquid is discharged therefrom, the flow of liquid from the pump and through discharge conduit 12 ceasing when the downward movement of the plunger 14 is terminated and the flow of liquid from nozzle 42 being simultaneously interrupted. In order that there may be no tendency for the liquid within the pump to harden this pump is maintained in heated condition while the apparatus is in operation, the pump casing having a vertical duct 'I'I formed therein. and paralleling the pump chamber, steam being conducted to the upper end of this duct through a conduit 18 and exhaust steam spection of Figure 5, the coating material duct I2 and the duct I8 for incoming steam are disposed in contiguous relationship from the vicinity of the pump chamber to a point just above the pressure operated nozzle device 4|. In this way liquid coating material passing upwardly through duct 12 is maintained hot and freely flowing so long as the apparatus is in operation.

Certain other elements of the apparatusare maintained in heated condition for various reasons, one being a heated trackway 82 for the freshly coated containers, illustrated most clearly in Figures 9, 10 and 11 and also indicated in' -7, the central portion of which is hollowed out to provide a steam chamber- 81 and is thereby maintained at a temperature above that at which the coating material will melt so that any drip from the containers passing across this bridging element will be maintained in liquid condition until it falls onto thev heated drip pan 83 by which it is led back to the receptacle II.

In Figure 20 all of the elements which are maintained in heated condition are diagrammatically illustrated and the various conduits for leading steam to these elements and conduits for conducting away exhaust steam and water of condensation are also shown. "It will beobserved that there is but a single steam line 89 for leading steam from a suitable source of supply, at the desired temperature, to the system of branch lines or conduits, and a single ofitake 98 for.

water of condensation and exhaust steam. The

various branch lines have previously been re-- ferred to for the most part and it need only be further stated that the ofitake line 22 leading from the heating chamber28 within the coating applying unit l8 has a branch 22' leading to the chamber 81 and a further branch 22 which leads to the container trackway 82, conduit 22 continuing to the drip pan 83, to the lower end of which is connected the steam and condensate return line 92. The condensate return line from the heated trackway 82 is indicated at 93 and that from chamber 81 is indicated at 93'. It will also be observed that the flow of steam to the steam chamber 25 beneath the container I I is controlled by means of a thermostatically actuated valve which valve is diagrammatically illustrated at 94 in Figure 20, the movements of the valve being.

governed by the action of a thermostat 95 which projects into the receptacle ll beneath the surand water of condensation being led' away from the bottom of the duct through the conduit 18. As will be perceived more readily from an iniace of the molten body of coating material therein. Should the temperature of the molten material fall the valve device 94 will be actuated and the valve opened to permit increased volumes operatively connected thereto and controlled thereby may be of conventional type.

As has been previously mentioned, a container which has progressed to the position in which it way is illustrated in chain lines in Figure 6, i. e., position R, has been completely coated and is ready for the next operation. Actuation of the pusher 3| through a single cycle of its movement causes the container R to move to the position R, the bottom of the container resting upon the spaced parallel rails I and IM of the heated trackway, these rails having peaks I00 and IM or relatively sharp ridges, upon which the container bottoms actually rest. The track rails are hollow and steam introduced at 22 will flow, in the direction of the arrows, forwardly through the channel I02 in the rail I00 to the cross duct I03 and thence rearwardly through the conduit or channel I04 to the ofitake line 93. Steam thus circulating through the rails of the trackmaintains these rails in highly heated condition and imparts heat to the bottoms of the containers although, by reason of the practically knife edge contact between the container bottoms and the peaks I00 and IN, the amount of heat thus imparted will not be substantial.

It will be observed that the parallel rails of the trackway are interconnected at a number of points by cross members I05 the upper surfaces of which are rounded and elevated somewhat above the plane of the peaks I00 and IN. The container bottom engaging portions of the rails are also upwardly sloped immediately adjacent the cross members I05 so that a container moving from right to left (Figures 9 and 10) along the heated trackway will move upwardly along these several inclines, which are indicated at I00a, as the several cross members I05 are approached in succession, the bottom of the container making full sliding contact with each of the cross members I05 over which it passes. Sliding contact with these cross members, which are of course heated, results in the removal by wiping of excess coating material from the bottoms of the containers so that, as each container reaches the terminal end of the trackway after having passed several of the wiping devices, the coating material upon its undersurface will be smooth and continuous. The cross members I05 likewise constitute devices for effecting rocking of the containers longitudinally of the trackway and facilitating distribution of the liquid coating material within the container over its bottom surface. Thusa container approaching a cross member I05 is tilted rearwardly and, after its center of gravity has passed over the cross member, will tilt forwardly, thus causing the coating material in liquid form resting upon its bottom to flow rearwardly and then forwardly, this action being repeated at each cross member so that, in the case of a trackway having four cross mem bers such as shown in Figures 9 and 10, each container passing thereon will be rocked first rearwardly and then forwardly four times. The liquid coating material upon the bottom of the container may likewise be flowed laterally if desired by the simple expedient of distorting the trackway so that the upper edges of the rails are at different elevations at various points along the length of the trackway. The trackway is fabricated of resilient metal and by means of the devices which are employed for the attachment of the same to the frame of the machine the desired distortion may be effected. Flowing of the liquid coating material back and forth over the container bottom causes all portions of the surface of the bottom to be washed with the liquid and insures that there are no uncoated areas.

The means for advancing each container along the trackway, from station R to station R and then successively to stations R R etc. comprises a chain conveyor the details of which it is unnecessary to describe but which is shown in plan in Figure 6. The two chains I01 and I08 of the conveyor are endless and disposed in a common horizontal plane with the adjacent reaches of the chains in parallelism and guided upon suitable rails or trackways. Container engaging lugs or elements are indicated at I00 and, as the conveyor is operated,.cooperating pairs of lugs are brought into simultaneous engagement with the rear wall of a container occupying the position R in Figure 6, elements I09 maintaining contact with the container thus engaged, and advancing the container with a continuous motion until the container has been passed over the heated trackway and completely through the cooling unit of the apparatus. Any suitable type of conveyor means may, however, beemployed foreffecting the desired movements of the containers. The means for reciprocating the pusher 3| in synchronism with the movements of the conveyor likewise forms no portion of the present invention and any suitable means for effecting such movements may be employed.

The end of the heated trackway 02 projects into the cooling unit of the apparatus, as may be clearly seen in Figure 3. The cooling unit comprises the insulated box or housing IIO shown in longitudinal section in Figure 12 and in transverse sections in Figures 13 and 14, the top portion III of which is attached by hinges II! (Figure 2) to the main or lower portion II3, apertures H4 and H5 in the ends of the housing being provided for the introduction and discharge of containers therefrom, and the several instrumentalities for the cooling or chilling of the coated containers are enclosed within this casing or housing. The conveyor chains I01 and I08 previously referred to extend through housing H0 and serve to continue the movement of the series of containers through this housing and out of the container discharge port II5 although, for the sake of clarity, these conveyor chains are not shown with the exception of the container engaging lugs I09 which are indicated in Figure 12.

As has been previously mentioned the forward end of the heated conveyor trackway projects through the aperture H4 and into the housing I I0 for a short distance. Beneath this portion of the trackway is a drip pan II6 for collecting any parafiin or other coating substance which may fall from the containers while still on the heated trackway, this drip pan sloping downwardly and discharging into the drip pan 83 previously mentioned. In Figure 12 of the drawings the containers indicated at R R. and R" are resting upon the heated trackway while the remainder of the containers shown, i. e., container R and those lying to the left of this container (Figure 12) have passed from this trackway and have their closed lower ends immersed in the body of cooling liquid indicated at I I8 which liquid, preferably water, rests in a longitudinally extending pan II9. Pan H9 is relatively long and narrow,

is shallow, and has upwardly and inwardly turned flanges H9. The liquid is cooled to a low temperature artificially and is of relatively high heat conductivity so that the temperature of each container bottom, which is of multi-ply construction, and also heavily coated with coating materal, is rapidly reduced. The liquid body H0 is of such length that by the time that container R reaches the position R both the multi-ply container R will cause it to move through aperture I I5. from where it may pass to other instrumentalities for charging and closing the same. It will be observed that header I2I has formed therein a longitudinally extending aperture I25 and that header I22 has a similar longitudinally extending aperture I26. These respective bores or apertures are in communication with the ends of a plurality of pipes or tubes I 21 extending longitudinally of pan I I9 and positioned approximately at the bottom of thepan. Cooling liquid is passed through the relatively small tubes I21 from one header to the other, by means to be hereinafter more particularly described, and the body of liquid in the pan thereby maintained at a low temperature preferably, when the liquid is water, just above the freezing point.

During the time that each container is moved from position R to position R that portion thereof which lies above the level of the liquid in pan- H9 is subjected to the action of a cooling gas, preferably air cooled to a low temperature, all of the exterior wall surfaces and also the interior wall surfaces being acted upon by the cooled gaseous streams, the effect of which is to chill and harden the coating material upon the upper portions of each container so that, when the container reaches the position indicated at R the coating material covering its entire upper portion, as well as the coating material on its bottom, has been thoroughly chilled and hardened.

A blower or fan is indicated at I30, this fan being mounted upon the bottom of the housing and the rotor of the fan being connected by means of a shaft I3I with a power source such as the electric motor I32 which is positioned without the housing and supported upon a bracket I33. The blower I30 is of the type which receives or draws in air axially of the rotor from both ends, arrows I34 indicating the directions of air inflow into the ends of the blower. The air thus drawn in is discharged transversely of the blower axis and the arrows I35, Figures 13 and 14, indicate the direction of flow of air discharged by the blower. A vertically extending baffle is indicated at I36 and the current of air discharged by the blower is directed upwardly between bafile I36 and the adjacent wall of the housing IIII, passes over a plurality of horizontally extend ng ducts I31 equipped with heat collecting fins I38 and thence upwardly toward the top of the housing, as indicated by the arrows in Figures 13 and 14. A cooling fluid, which may be either a liquid or a gas. is circulated through tubes I31 by means hereinafter to be described and the air passing past these tubes is cooled by contact therewith and with the heatcollecting fins I38. Toward the top of the housing the stream of air meets a plu rality of inclined bafilng plates I39, I40 and MI, rigidly supported in position, which serve to direct the air upwardly and'inwardly toward the "series'of containers so that the adjacent longitudinally extending side surfaces of these containers are directly subjected'to impinging air streams and the transversely extending forward and rear side walls of the container are likewise subjected to the action of such streams. A certain amount of the upflowing air stream will pass over the lower or leading edge of the baflle plate MI and along the lower surface of the top of the housing where it will meet and be deflected downwardly by the curved bafile I42 into the interiors of the several containers, thus causing rapid circulation of air within these interiors and direct cooling of the inner coating of coating material. A substantial stream of cooled air will continue past the deflector I42 and will be turned and again passes to the fan 'or blower for recirculation. By the means described, therefore, a body of cooling gas may be continuously circulated within the housing and caused by bafiling devices to fiow past all exposed surfaces of the series of containers therein.

While the housing is not gas-tight, having the open apertures H4 and H5 in its ends, there will be but little cooled air escape in the ordinary operation of the unitand naturally any air escaping will be replenished automatically. In Figure 14 a small tube is indicated at I46, the discharge end of which overlies the liquid pan II9. It 'is through this tube that a regulated flow of liquid is passed into the liquid pan to replace that which is carried from .the unit upon the bottoms of the containers passing therethrough. The flow of liquid may be regulated by a needle valve and any excess liquid supplied will pass over the header I2I and fall onto a drip pan I41, by which it is conducted to a point of discharge.

The 'means for circulating a cooling fluid through the conduits previously described is diagrammatically illustrated in Figure 21. In this figure a supply main is indicated at I 50, this main leading from any suitable source of cooling fluid. While the cooling fluid may be either in gaseous or liquid form, the apparatus which has been illustrated is one which has been primarily designed for use with brine as a cooling medium, brine being introduced into the system from a suitable source through the supply main I50 at a temperature which may vary between zero degreesand 20 F. From main I50 a branch line I5I leads to the system or battery of air cooling tubes I31 and from this series of tubes the brine passes into tubular casing I52, thence into conduit I53 and finally to discharge main I 54 by which it is conducted to a brine cooling and recirculating mechanism which is not illustrated. A second branch line leading from main I 50 is indicated at I55, this branch leading to header I22 which header, as has been previously explained,

streams.

is conducted through conduit I56 to a cylindrical housing I51 and is thence conducted through conduit I58 to the brine return main I54.

The housings I52 and.I51 previously referred to contain thermostatic elements I59 and I66 respectively, indicated in dotted lines, which elements are preferably of the fluid expansion type and either mechanically or by fluid pressure means operatively connect two control valves I6I and I62 respectively, valve I6I controlling the flow of cooling liquid through branch II to the air cooling tubes I31 and valve I62 controlling the flow of brine through conduit I55 to the liquid cooling tubes I21. It will be observed that the thermostatic elements I59 and I60 are both 'so disposed in the fluid circulating system that each is encircled by a body of brine which has already performed its cooling functions and hence it is clear that valves I6I and I62 are controlled in accordance with variations in the temperatures of the outflowing brine The system is entirely automatic in operation and valves I6I and I62 are of course independently regulated so that the body of water in pan II9 may be subjected to the'action of additional or reduced amounts of cooling brine, without requiring the circulation of additional or reduced amounts of cooling brine through the air cooling coils I31 or vice versa. It will be understood that no novelty is claimed for the details of construction of the thermostat means for controlling the operationof the valves I6I and I62 respectively and that any suitable thermostatic devices available may be employed. Preferably, however, thermostats are of the gas expansion type and the variations in gas pressure Within thermostatic elements I59 and I62 cause the operation of bellows devices within the housings diagrammatically illustrated at I63 and I64 respectively, which bellows devices are directly connected to the valves through valve stems I65 and I66.

It is thus seen that a cooling unit has been provided, within which freshly coated containers are subjected to the action of cooling mediahaving different heat conducting properties so that, notwithstanding the fact that certain j'portions of the containers are more difficult to cool than others, all portions thereof are brought to completely cooled condition practically simultaneously. It is apparent that the method of cooling disclosed may be practiced in structures which differ widely from that which has been disclosed by way of example. Furthermore any suitable gas may be employed rather. than air and the actual cooling of the air and liquid may be effected by an artificial cooling mechanism of the gas expansion type, rather than of the brine circulation type.

The heated trackway 'lflll also embodies three cross connecting webs IOIl each provided with a central slot IIIIJ (see Figure and lateral apertures I00 A securing screw IIlIl passes downwardly through each slot and set screws I 00 pass through the apertures I06 the securing screw entering a threaded recess in a supporting member vS the ends of which are attached to rails S by brackets 8*, one of which is shown in Figure '7. By manipulating the set screws and securing screws the trackway may be raised or lowered as desired and also tilted or distorted to obtain the desired inclination of a container passing over the same and hence the desired distribution of coating material over its bottom.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. Mechanism of the class described comprising, in combination, a container handling device for placing bottom end lowermost upon a conveyor, an open topped tubular paper container the bottom of which is closed and the inner wall surfaces of which are coated with coating material in molten condition, mechanism spacedfrom said device for chilling and solidifying such molten coating, and a conveyor for receiving such an interiorly coated container deposited thereon at one point by said'device and transmitting the same to said chilling mechanism, said conveyor including means for heating the container bottom to maintain the molten material collected thereon in molten condition and means to rock the container as it advances so that such molten material will be caused to flow over all areas of the container bottom.

2. Mechanism of the class described comprising, in combination, a container handling device for placing bottom end lowermost upon a conveyor, an open topped tubular paper container the bottom of which is closed and the inner wall surfaces of .which are coated with coating material in molten condition, mechanism spaced from said device for chilling and solidifying such molten coating, and a conveyor for receiving such an interiorly coated container deposited thereon at one point by said devices and transmitting the same to said chilling mechanism, said conveyor including a trackway upon which the containers rest and along which they are moved, and means for heating the trackway, said trackway having uneven container engaging surfaces to cause the containerto rock as it adadvances so that molten material collected on the container bottom will be maintained in liquid condition and caused to flow over all areas of the container bottom before solidifying.

3. Mechanism of the class described comprising, in combination, a container handling device for placing bottom end lowermost upon a conveyor, an open topped tubular paper container the bottom of which is closed and the inner wall surfaces of which are coated with coating material in molten condition, mechanism spaced from said device for chilling and solidifying such molten coating, and a conveyor for receiving such an interiorly coated container deposited thereon at one pointby said device and transmitting the same to said chilling mechanism, said conveyor including a trackway upon which the containers rest and along which they are moved, and means for heating the trackway, said trackway having a plurality of spaced transversely extending raised portions over which the containers move and which cause the containers to rock forwardly and rearwardly as they advance.

4. Mechanism of the class described comprising, in combination, a container handling device for placing bottom end lowermost upon a conveyor, an open topped tubular paper container the bottom of which is closed and the inner wall surfaces of which are coated with coatin material in molten condition, mechanism spaced from said device for chilling and solidifying such molten coating, and a conveyor for receiving such an interiorly coated container deposited thereon at one point by said device and transmitting the same to said chilling mechanism, said conveyor including a trackway upon which the containers 

